A computerized test system for digital audio devices which is based on a personal computer with an internal or external sound card can provide a wide range of desirable functions for testing electroacoustical characteristics of the digital audio devices. Using a personal computer coupled to standard sound card keeps costs of hardware components at a very moderate level despite an ability to build a highly sophisticated and flexible test system with a user friendly graphical interface.
However, substantial challenges persist in unlocking the performance potential of such personal computer based test systems for accurate and fast measurements of the electro-acoustic characteristics of the digital audio devices. Standard sound cards are generally not designed for use in critical test and measurement systems and therefore lack tight control of frequency responses of test signal generating channels and response signal receipt channels. This lack of accuracy may be contributed to a number of different factors such as frequency response variations of analog input and output buffers or amplifiers, aliasing filters, ND and D/A converters etc. This means that absolute levels of test signals and response signals presented to, and generated by, the digital audio device are inaccurate and therefore lead to an inaccurate determination of the electro-acoustic characteristics of device under examination.